Conventionally, a ladder shaped chassis frame is provided in a small truck or a vehicle called a “sport-utility vehicle (SUV)” as described in, e.g., Patent Documents 1 and 2. The chassis frame is formed in the ladder shape by a pair of right and left main frames (also called “side frames”) extending in a vehicle length direction (vehicle longitudinal direction) and a plurality of cross-members each connecting the main frames together. Each of the main frames includes a narrow part provided such that a distance between the narrow parts of the main frames is short; a wide part provided such that a distance between the wide parts of the main frames is longer than that between the narrow parts; and a widened part positioned between the narrow part and the wide part and provided such that a distance between the widened parts of the main frames is increased toward the rear.
Typically, in the foregoing vehicle, power of an engine arranged in an engine room positioned in a front part of the vehicle is transmitted to rear wheels through a transmission, a propeller shaft, and a rear differential gear unit (in the case of a 4WD vehicle, a power transfer unit is provided between the transmission and the propeller shaft). The propeller shaft includes a front shaft and a rear shaft connected together through a joint (e.g., a universal joint). The vicinity of a rear end of the front shaft is supported by a center bearing.
In addition, in the foregoing vehicle, a fuel tank configured to store fuel to be supplied to the engine is provided. Typically, the fuel tank is arranged on one side of the rear shaft of the propeller shaft in a vehicle width direction.
Upon a frontal collision of the vehicle, a front end part of the propeller shaft is, due to, e.g., backward movement of the engine, pushed toward the rear, and therefore the propeller shaft is bent at the position of the joint. In such a case, e.g., Patent Document 1 has proposed that a propeller shaft is guided so as to be bent in a predetermined direction in order to prevent a collision of the propeller shaft with the fuel tank. Specifically, a connection wire connects between the center bearing and a front part of the wide part of the main frame provided on a side opposite to the fuel tank relative to the center bearing.